This application claims the priority of Italian application TO 96 A 000249 filed Mar. 29, 1996 in Italy,
The invention relates to a locking device for a selector lever for an automatic gearbox.
A locking device preamble is already known from European Patent EP O 413 116 B1. The selection device disclosed there for an automatic gearbox has a selector lever which can be pivoted in two gear-shift gates. When the selector lever is in the first gear-shift gate, it acts directly upon the automatic gearbox by means of a transmission device. When the selector lever is shifted into the second gear-shift gate, it is detached from the transmission device and a locking device prevents the transmission device from being moved out of the intended position in an undesired manner. The locking device comprises a locking member which is mounted on the transmission device and which is pivotable into an opening arranged stationary with the housing. The locking member is actuated by the pivoting movement of the selector lever from the first gear-shift gate into the second gear-shift gate and is disengaged again by a reverse pivoting movement from the second gear-shift into the first gear-shift gate.
In addition, a longitudinal locking means on the selection device is likewise known from this EP O 413 116 B1 document, in which the longitudinal locking means is effective in the first gear-shift gate during the longitudinal pivoting of the selector lever. With the aid of this longitudinal locking means the longitudinal movement of the selector lever is restricted to specific positions provided in the first gear-shift gate and the selector lever is held in pre-set positions in the first gear-shift gate. The longitudinal locking means comprises a slide which is arranged on the selector lever and which is movable radially to the pivoting movement thereof. A projecting pin, which engages in an indentation in the housing, is mounted on the slide. An actuating device extends from the slide to a button which is arranged at the upper end of the selector lever and which can be pressed by the driver in order to unlock the longitudinal locking means. In this case the slide is moved out of its spring-loaded rest position and the pin is disengaged from the indentation, so that the selector lever is freely pivotable.
In contrast, an object of the invention is to provide a locking device which is inexpensive in design and simple to assemble.
This object is attained by providing an assembly wherein a locking device for the selector lever and a locking assembly holding the selector lever in respective shifting positions when operating in a transmission shifting gate have the same actuating direction. For this purpose it is provided that the locking device and the longitudinal locking assembly interact with each other when the selector lever is in the first gear shift gate. In this case the operational reliability of the locking device is increased in an advantageous manner since the locking device is now unlocked by way of the longitudinal locking assembly so that the transmission device for the automatic gearbox is released only when the selector lever is moved. The movements of the locking device and the longitudinal locking assembly are now linked together by the reciprocal action.
Advantageous features of preferred embodiments of the invention are set out below.
In certain preferred embodiments it is proposed that the locking device and the longitudinal locking assembly are actuated jointly. An unlocking of the selector lever performed consciously by the driver thus leads to the direct release of both the locking device and the longitudinal locking assembly, so that undetermined intermediate states are avoided.
Alternatively, it is proposed according to certain preferred embodiments that the longitudinal locking assembly actuates the locking device. On the one hand this can be carried out in that the longitudinal locking assembly acts upon the locking device, and the longitudinal locking assembly and the locking device are thus jointly unlocked. Alternatively, it is possible for the longitudinal locking assembly to unlock the locking device when the longitudinal locking assembly enters its position provided in the first gear-shift gate. By releasing the locking device, the transmission device is then released at the moment at which the longitudinal locking assembly becomes effective again after the selector lever is pivoted back into the first gear-shift gate. These embodiments have in common the advantage of reliably preventing an uncontrolled movement of the transmission device at all times on the one hand and at the same time of ensuring the reliable unlocking of the locking device and the longitudinal locking assembly on the other hand.
As additionally proposed in certain preferred embodiments, the locking device and the longitudinal locking assembly can have a common matching member. This results in a reduced manufacturing outlay, and in addition the locking device and the longitudinal locking assembly need not be separately adapted to each other in their position.
In a preferred embodiment the locking device is constructed in the form of a radial slide which engages in an indented profile arranged on the housing. The longitudinal locking assembly likewise constructed in the form of a slide has a projection which engages in the same indented profile in the housing. In accordance with a first embodiment, as the selector lever is pivoted into the first gear-shift gate the projection pushes the radial slide out of the indented profile and thus disengages the locking device. In the case of a second, alternative embodiment, both the radial slide and the projection remain in engagement with the indented profile when the selector lever is pivoted into the first gear-shift gate. The radial slide has en entrapment member provided therewith which cooperates with the projection and transmits the movements of the slide of the longitudinal locking assembly to the radial slide and thus the locking device so that the longitudinal locking means and the locking device are unlocked jointly.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.